Image sensor with aluminum grid pattern having openings and copper dummy patterns covering the openings

Abstract

An image sensor includes a first chip that includes a pixel region and a pad region, and a second chip that is in contact with one surface of the first chip and includes circuits that drive the first chip. The first chip includes a first substrate, an interlayer insulating layer disposed between the first substrate and the second chip, first interconnection lines disposed in the interlayer insulating layer, a conductive pad disposed in the pad region between the second chip and the first interconnection lines, and a recess region formed in the pad region that penetrates the first substrate and the interlayer insulating layer and exposes the conductive pad.

What is claimed is: 
     
       1. An image sensor, comprising:
 a first chip that includes a pixel region and a pad region; and 
 a second chip that is connected with one surface of the first chip and includes a first connection pad, a second connection pad, second interconnection lines, and circuits that drive the first chip, 
 wherein the first chip comprises:
 a first substrate; 
 an interlayer insulating layer disposed between the first substrate and the second chip; 
 first interconnection lines disposed in the interlayer insulating layer; 
 a conductive pad entirely disposed within the interlayer insulating layer in the pad region of the first chip between the second chip and the first interconnection lines; 
 a metal pattern disposed in the pixel region between the second chip and the first interconnection lines and disposed at a same level as the conductive pad, wherein the metal pattern is connected to the second chip by a conductive connection pad; 
 a third connection pad disposed between the conductive pad and the second chip; 
 a fourth connection pad disposed between the conductive pad and the second chip; and 
 a recess region formed in the pad region that penetrates the first substrate and the interlayer insulating layer and exposes the conductive pad, 
 wherein the conductive pad is disposed on and connected to the third connection pad and the fourth connection pad, 
 wherein the first connection pad is connected to the third connection pad and the second connection pad is connected to the fourth connection pad, 
 wherein the conductive pad is connected to the second chip through the third and first connection pads, and through the fourth and second connection pads, 
 wherein the first and second connection pads are connected to the second interconnection lines, and 
 wherein the metal pattern includes a first barrier layer disposed on its bottom surface, the conductive connection pad includes a second barrier layer disposed on its top surface and sidewall, and a connection portion of the conductive connection pad and the metal pattern has a step structure in which the second barrier layer penetrates the first barrier layer of the bottom surface of the metal pattern. 
 
 
     
     
       2. The image sensor of  claim 1 , wherein the first connection pad is directly connected to the third connection pad and the second connection pad is directly connected to the fourth connection pad. 
     
     
       3. The image sensor of  claim 1 ,
 wherein the first connection pad and the third connection pad include a same metal, and 
 wherein the conductive pad includes a metal that differs from that of the first connection pad and the third connection pad. 
 
     
     
       4. The image sensor of  claim 3 ,
 wherein the conductive pad includes aluminum, and 
 wherein the first connection pad and the third connection pad include copper. 
 
     
     
       5. The image sensor of  claim 3 , wherein the conductive pad is thicker than the first connection pad. 
     
     
       6. The image sensor of  claim 3 , wherein the metal pattern includes a same material as the conductive pad. 
     
     
       7. The image sensor of  claim 6 ,
 wherein the metal pattern has a grid shape that includes openings. 
 
     
     
       8. The image sensor of  claim 7 ,
 wherein the first chip further comprises: a contact plug that connects the first interconnection lines to the conductive pad, and 
 wherein the contact plug is not provided in the pixel region between the metal pattern and the first interconnection lines. 
 
     
     
       9. The image sensor of  claim 1 , wherein the conductive pad comprises a barrier layer at each of a top surface and a bottom surface of the conductive pad, and
 wherein the recess region penetrates the barrier layer. 
 
     
     
       10. The image sensor of  claim 9 , wherein the barrier layer is not provided on a sidewall of the conductive pad.